Bottlehead Forum

Bottlehead Kits => BeePre => Topic started by: Deke609 on September 26, 2020, 12:19:23 PM

Title: The New BeePre Pure Speculation Thread
Post by: Deke609 on September 26, 2020, 12:19:23 PM
So, we know a new BeePre is coming. What else do we know? Only this much:

A universal power transformer is indeed part of what's up.

Note the phrase "part of what's up".  So there's more. So let's speculate what it'll be! 

In the thread from which PB's above quote is taken, someone expressed hope that the filament regulator will be immune to mains voltage sag -- b/c when the reg drops out you get a lot of hum/buzz.  I think the new universal power trafo with different primary winding configurations will take care of this in most cases -- but perhaps the voltage of the LV secondary will get bumped a bit? And maybe permit a bit of smoothing before being sent to the reg?  I doubt this last bit b/c that would be overkill (which, of course, is why I included a CLC filter before the fil reg in my Beepre rebuild  ;D )

My biggest question is whether the attenuator will be moved from the input to the output to increase SNR, as in the Moreplay.  If yes, I really hope there's a mod to make this work with existing Beepre's.  IIRC, PB mentioned in another thread in the last year that to do this other circuit changes are needed to maintain the output impedance of the amp.  I'm not sure if moving the attentuator would make much difference for those who keep the Beepre attentuators turned up pretty high -- but I'm guerssing it might make an audible difference for those who only use the first two (highest dB reduction) positions of the coarse attenuator.

What else?  Let the wild guessing begin!

cheers, Derek
Title: Re: The New BeePre Pure Speculation Thread
Post by: Paul Birkeland on September 26, 2020, 02:16:17 PM
There will not be any backwards compatibility between what we are up to now and what we are working on for the release.
Title: Re: The New BeePre Pure Speculation Thread
Post by: Deke609 on September 26, 2020, 03:07:39 PM
J. H. C.! I might be building a new Beepre next year!   :o With luck I can build the new circuit in my "BigBy" chassis.
Title: Re: The New BeePre Pure Speculation Thread
Post by: Deke609 on September 27, 2020, 05:55:01 AM
I take comfort in knowing that I am not the only recent Beepre builder that will likely be building the new version when it gets released.

I am all but certain that, like me, Jameson is  weighing whether he can make use of two Beepre's and I'd even guess that he's leaning towards (a) using the new premium preamp in his main rig; (b) in that same main rig, replacing the SII with Monomours to drive his Kaiju Jager tweeters; and (c) using the "old" BP and SII as a kickass secondary system -- perhaps office or for tv.

Jameson: am I close?   ;D

cheers, Derek
Title: Re: The New BeePre Pure Speculation Thread
Post by: oguinn on September 27, 2020, 09:01:16 AM
I don’t want to talk about it ;)
Title: Re: The New BeePre Pure Speculation Thread
Post by: Alby0521 on September 30, 2020, 01:42:05 PM
When is the new Beepre supposed to come out?
Title: Re: The New BeePre Pure Speculation Thread
Post by: johnsonad on September 30, 2020, 02:00:55 PM
I predict it will sound fantastic, have a great manual and support from the BH team. If it improves on the BeePre that will be one nice preamp!
Title: Re: The New BeePre Pure Speculation Thread
Post by: Alonzo on September 30, 2020, 05:38:38 PM
Here's a wild speculation:
Universal transformer, TI DC 6v boost circuit board added to power supply, extra input so now 3 in, 3 out, change out the 80 ohm resistors for Ohmite ceramic for a cooler top plate, individual pots instead of a balance circuit or maybe BeeQuiet being standard.
Title: Re: The New BeePre Pure Speculation Thread
Post by: oguinn on September 30, 2020, 10:39:38 PM
If it’s anything like previous stepwise updates they’ve made to the Eros, it might just be a universal transformer and a change to the layout to make things simpler to construct and troubleshoot.
Title: Re: The New BeePre Pure Speculation Thread
Post by: Doc B. on October 01, 2020, 05:41:26 AM
Even I don't know what the final changes will be yet. We have a tentative plan to listen to a couple of prototypes next week, after which I will make some final decisions. The voltage sag issue has been addressed. The power supply is different than the one in the original BeePre.
Title: Re: The New BeePre Pure Speculation Thread
Post by: Deke609 on October 01, 2020, 06:30:51 AM
We have a tentative plan to listen to a couple of prototypes next week ...

Man, testing different PJ/PB prototypes ... that's a pretty sweet part of the job!

cheers, Derek
Title: Re: The New BeePre Pure Speculation Thread
Post by: Raymond P. on October 01, 2020, 10:03:31 AM
Even I don't know what the final changes will be yet. We have a tentative plan to listen to a couple of prototypes next week, after which I will make some final decisions. The voltage sag issue has been addressed. The power supply is different than the one in the original BeePre.


Please post some pics of the prototypes, inside and out. To respect the theme of this thread, I speculate the new BeePre will be in my system in the future.
Title: Re: The New BeePre Pure Speculation Thread
Post by: Paul Birkeland on October 01, 2020, 10:11:29 AM
Please post some pics of the prototypes, inside and out.
That's always an iffy proposition.  Some of the stuff we (more often than not me) build sucks horribly and should never see the light of day, and what we really wouldn't want is to get traction on a prototype that performs poorly!
Title: Re: The New BeePre Pure Speculation Thread
Post by: Raymond P. on October 16, 2020, 06:45:29 PM
I saw a picture of a BeePree II prototype on the Bottlehead Instagram feed and was wondering what the chassis size is. (Gotta make sure I have space. :-) )


BTW, that power transformer looks massive, like the Kaiju's.
Title: Re: The New BeePre Pure Speculation Thread
Post by: Paul Birkeland on October 17, 2020, 05:20:00 AM
It is a 10x16 like the Kaiju with the same power transformer.
Title: Re: The New BeePre Pure Speculation Thread
Post by: Deke609 on October 17, 2020, 09:37:17 AM
So Doc B. has chosen the winning prototype?

When will we learn more? I imagine putting together the assembly manual will take a while. Any chance of a brief circuit description in advance, preferably highlighting changes from the previous version?

cheers and thanks, Derek
Title: Re: The New BeePre Pure Speculation Thread
Post by: Paul Birkeland on October 17, 2020, 10:23:10 AM
Yeah, all of this started in April 2018 with this prototype.  Ultimately all I was really wanting to do here was to make myself a BeePre that looked more like my Kaiju and to mess with a BeePre  powered with the Kaiju power transformer.  I used the new Kaiju DC filament supply board instead of the specialty BeePre filament regulator which freed me up from being locked into the BeePre operating point and allowed a little extra flexibility.  Being able to adjust the operating point meant that I could move the attenuators to the output and not overdrive the 300B in the process. 
Title: Re: The New BeePre Pure Speculation Thread
Post by: Paul Birkeland on October 17, 2020, 10:27:06 AM
After the red prototype, we explored the possibility of different packing and remote control options.  All those extra metal panels drove the cost of the kit way up, and the remote attenuator would have required me sitting down with the boards we ordered and doing surface mount soldering to each one to prep them before shipping, or paying a board house to do assembly.  Stuff like that really messes with lead times, and a $3000 preamp kit wasn't sounding like such a hot idea, so this one didn't make it to the public.
Title: Re: The New BeePre Pure Speculation Thread
Post by: Raymond P. on October 17, 2020, 10:42:09 AM
The Bottlehead Instagram has a picture of the underside and showed a stepped attenuator. Is the stepped attenuator an upgrade kit? I hope the basic potentiometers with L/R balance control are still available.
Title: Re: The New BeePre Pure Speculation Thread
Post by: Paul Birkeland on October 17, 2020, 10:43:46 AM
So now we arrive at the current design, which from my records is the 5th or 6th prototype (not all of them make it to getting built).  This iteration was inspired by the simplicity of the Moreplay, and in essence what I built could be called a BeePlay. It is a boiled down version of the circuit with the Kaiju DC filament supply but just a CRCRC high voltage supply.  Biasing and plate loading are done with resistors to dramatically decrease the amount of initial debugging, and we just plug/block off the holes for the extra tubes/jacks that come with the upgrades.  This will be the "stock" BeePre 2 offering. 

On Friday, I brought up this basic BeePre preamp and several of the upgrade modules, and we installed them and listened to the various options. 

Ultimately one upgrade will be a BeeQuiet attenuator with completely different values to better work with this new circuit, but this upgrade will also come with active loads for the 300B.  The combination of the lower impedance of the new BeeQuiet and the resistive loading in the stock circuit isn't optimal, hence the combination of the attenuator and C4S board offered together.

The second upgrade module will populate the rear two 9 pin sockets with a dissimilar dual triode that provide individual shunt regulators for both channels as well as adding a cathode follower buffered output that decreases the output impedance of the kit substantially.  This upgrade will also provide balanced outputs similar to the BeePre 1.

The primary benefits of the new design vs. the old are:
Title: Re: The New BeePre Pure Speculation Thread
Post by: Raymond P. on October 17, 2020, 10:58:53 AM
My understanding of the upgrades may not be correct, but is sounds like the new attenuator design needs the C4S loads for optimal performance. But is the reverse also true? Meaning, will the preamp work just as well with C4S loads with the basic pots?


I'm hoping the C4S loads (w/o the attenuator) can be a stand alone upgrade.


Thx.
Title: Re: The New BeePre Pure Speculation Thread
Post by: Paul Birkeland on October 17, 2020, 11:02:42 AM
My understanding of the upgrades may not be correct, but is sounds like the new attenuator design needs the C4S loads for optimal performance. But is the reverse also true? Meaning, will the preamp work just as well with C4S loads with the basic pots?
Yes, the new attenuator needs the C4S loads for optimal performance. 

I'm hoping the C4S loads (w/o the attenuator) can be a stand alone upgrade.
That is not in the plan as of now.  The new design could, however, allow you to get creative and have both the balance control and the BeeQuiet attenuator.  You'd have to move the balance control to a hole on the wood base, but it's now possible with this design.
Title: Re: The New BeePre Pure Speculation Thread
Post by: Doc B. on October 17, 2020, 11:29:22 AM
Everyone wants to know about the upgrades but no one asks about how it sounds?
Title: Re: The New BeePre Pure Speculation Thread
Post by: Paul Birkeland on October 17, 2020, 11:32:05 AM
Everyone wants to know about the upgrades but no one asks about how it sounds?
Doc B. didn't want to let me take it home!
Title: Re: The New BeePre Pure Speculation Thread
Post by: Deke609 on October 17, 2020, 11:49:25 AM
Everyone wants to know about the upgrades but no one asks about how it sounds?

I do, and specifically the stock, stock+C4S/BQ and Stock+C4S/BQ+shunt-reg/cathode-follower as compared to the BP1+BQ. 

Tell us everything Doc!

cheers, Derek
Title: Re: The New BeePre Pure Speculation Thread
Post by: Thermioniclife on October 17, 2020, 11:53:24 AM
How about the Microphony?
Title: Re: The New BeePre Pure Speculation Thread
Post by: Deke609 on October 17, 2020, 11:58:25 AM
See primary benefit #2:

The primary benefits of the new design vs. the old are:
  • Replacing the two single voltage power transformers with a new universal power transformer.
  • Reducing the severity of microphonics and apparent noise in the circuit through relocating the attenuator and using a different 300B operating point.
  • Offering a far easier to build stock circuit and modularizing the more difficult components as future (optional) upgrades.
  • Providing some additional space with a larger chassis plate that matches the Kaiju.
  • Low line voltage regulator dropout is now nearly impossible through the combination of using the Kaiju DC filament regulator, the universal power transformer, and a different circuit design.

Title: Re: The New BeePre Pure Speculation Thread
Post by: Thermioniclife on October 17, 2020, 12:24:53 PM
Yeah I read that but I would like to hear from the designers.
Title: Re: The New BeePre Pure Speculation Thread
Post by: Raymond P. on October 17, 2020, 01:06:23 PM
Everyone wants to know about the upgrades but no one asks about how it sounds?
I just assumed whichever becomes the final product will sound great. :-)
Title: Re: The New BeePre Pure Speculation Thread
Post by: Paul Birkeland on October 17, 2020, 02:00:48 PM
Microphony is greatly reduced.  The revised design (we'll assume the attenuator upgrade is installed because it makes the math easier) will be at worst only 4dB less microphonic than the BeePre 1.0, but every reduction from -0, -0 on the BeeQuiet attenuators reduces the microphony by that amount of attenuation.

So if you find you listen to -9dB on the coarse switch and -0dB on the fine switch typically, then the new BeePre with the BeeQuiet upgrade would have 13dB less microphony than BeePre 1.0.  For those who happen to use a high gain solid state amplifier with a BeePre or who use a Kaiju with super sensitive speakers will find that they listen with the BeeQuiet attenuators turned way down most of the time, and the new design would be a very dramatic change. 

For reference I don't even bother using my vinyl coated lead rings with the new design.
Title: Re: The New BeePre Pure Speculation Thread
Post by: johnsonad on October 17, 2020, 02:17:57 PM
I’m excited to hear it and even more excited about the low part count.
Title: Re: The New BeePre Pure Speculation Thread
Post by: Natural Sound on October 17, 2020, 04:17:34 PM
Nice to see some of the details coming out. I'd love to hear some listening impressions from the Bottlehead team.

One of my visual observations is that there is tons of room around the input jacks! Interconnect junkies like myself now have lots of room to move around. I really like that.

Is the overall gain lowered in the new design? Often times I feel like I need to dump excessive gain somehow. Getting a few extra dB gain from a phono pre is usually desirable. Excessive gain in a pre amp often is not.

I'm also interested in cost. But I understand that detail probably isn't settled quite yet. I'll be patiently waiting for that.

It's always nice to have something to look forward to. Especially in these trying times. Thanks for your continuous improvements guys.
Title: Re: The New BeePre Pure Speculation Thread
Post by: Paul Birkeland on October 17, 2020, 05:38:18 PM
Is the overall gain lowered in the new design? Often times I feel like I need to dump excessive gain somehow. Getting a few extra dB gain from a phono pre is usually desirable. Excessive gain in a pre amp often is not.
It should be slightly lower, but not noticeable.  I need to pop into the workshop to do some measurements at some point, but I would expect the overall gain to be 8dB +/-2dB.  That's about as low as most preamps get.

I'm also interested in cost. But I understand that detail probably isn't settled quite yet. I'll be patiently waiting for that.
I'm working on this.  I am expecting the basic BeePre to be close to the cost of BeePre 1.

-PB
Title: Re: The New BeePre Pure Speculation Thread
Post by: Paul Birkeland on October 17, 2020, 06:42:33 PM
If you're jonesing for a BeePre with EML tubes or other slightly-off 300Bs that need a little more filament current, that can now be more easily accommodated with the new filament arrangement.  Trimming it out would be the same procedure used for the Kaiju.
Title: Re: The New BeePre Pure Speculation Thread
Post by: Alby0521 on October 18, 2020, 08:29:29 AM
Hello,

All is very exiting!!!
When do you expect to release it on the market? 2 weeks, 2 months, 1 year? A ballpark idea?

Thanks.

AB
Title: Re: The New BeePre Pure Speculation Thread
Post by: Paul Birkeland on October 18, 2020, 09:11:11 AM
I have another prototype I need to build to get things closer to the final product, then the one after that can be built for the manual shoot.  Tentatively that manual shoot would be in early November, and we would have pricing and ordering available shortly after that.
Title: Re: The New BeePre Pure Speculation Thread
Post by: jjvornov on October 19, 2020, 03:17:39 AM
Now I know what my winter Bottlehead kit project will be! I was worried that after the Monamour build, I was done. This is exciting as the BeePre 1 is an amazing preamp as it is, but having the buzz and microphonic fixed is worth building a new one.

Title: Re: The New BeePre Pure Speculation Thread
Post by: RPMac on October 22, 2020, 10:48:05 AM
With the new op points, will the 6A3 still be an option?
Title: Re: The New BeePre Pure Speculation Thread
Post by: Paul Birkeland on October 22, 2020, 11:07:28 AM
With the new op points, will the 6A3 still be an option?

A mild modification will allow this (jumpering across a few resistors with pieces of wire).
Title: Re: The New BeePre Pure Speculation Thread
Post by: RPMac on October 22, 2020, 12:10:57 PM
A mild modification will allow this (jumpering across a few resistors with pieces of wire).
Can it be safely done using a switch?
Title: Re: The New BeePre Pure Speculation Thread
Post by: Paul Joppa on October 22, 2020, 12:24:26 PM
How safe is safe enough?

If it's a switch, then it's easy to accidentally put 6.3vDC on a 300B filament, which is enough to damage the 300B.
Title: Re: The New BeePre Pure Speculation Thread
Post by: Paul Birkeland on October 22, 2020, 03:47:13 PM
I am 100% in agreement with PJ.  I've never met someone with a piece of tube gear that had a filament voltage switch who hadn't destroyed either tubes or the amp itself.
Title: Re: The New BeePre Pure Speculation Thread
Post by: RPMac on October 22, 2020, 04:51:53 PM
Thank you for your answers, that’s why I asked.
Title: Re: The New BeePre Pure Speculation Thread
Post by: triode on October 22, 2020, 06:04:43 PM
I am 100% in agreement with PJ.  I've never met someone with a piece of tube gear that had a filament voltage switch who hadn't destroyed either tubes or the amp itself.

Oops, I just finish installing a filament switch in my Foreplay III to accomodate both 12AU7 and 6CG7
Title: Re: The New BeePre Pure Speculation Thread
Post by: pboser on October 23, 2020, 08:33:32 AM
I have to admit that I have cooked some tubes on my tube tester by not checking the filament switch. 
Title: Re: The New BeePre Pure Speculation Thread
Post by: makarushka on October 23, 2020, 08:34:20 AM
Great to hear regarding the improvements in microphony reduction! My original BeePre was one of the best preamps I've owned overall, including many custom DHT units of various designs, a purist but really insane build based on we437a with Tango NP-126 outputs -- real "wire with [a lot of ] gain", and several commercial units of certain pedigree like EAR 912 and AtmaSphere MP-3. Excessive microphonics was the ONLY reason I ended up selling the BeePre -- was just too much for me to live with. The sound otherwise was just sublime -- had everything: transparency, bloom, phenomenal bandwidth, just the right amount of gain, etc. In retrospect, I should have re-worked that unit further to produce better mechanical isolation but I felt that with all the tweaks I made I got close to limit.

With that in mind, would you guys -- Doc and Paul -- consider some further mechanical isolation for the 300B socket mounting? Or at least, make the opening just large enough so that the base of the tube can go through just so we can mount the socket on rubber standoffs ourselves? Or do you feel strongly that with the new design even this is not needed?

As far as the sound, and this is of course very subjective, no loss of clarity/immediacy/transparency with the extra follower stage? That was the beauty of the old one -- nothing but a DHT in the signal path. But if you guys say it sounds good, it sounds good -- I've built a couple of your kits and I trust your sonic reference -- and like it a lot.

I am pretty sure I'll be ordering this one :)
Title: Re: The New BeePre Pure Speculation Thread
Post by: Doc B. on October 23, 2020, 09:11:17 AM
I may have some experiential advantage here due to having taken a pragmatic approach to dealing with the issue. The amount of suspension necessary to effectively limit vibration transfer from the chassis to the socket would have the socket bouncing around like a baby in one of those Johnny Jump Up suspended chairs. With a top heavy 300B this floppy suspension would be a recipe for disaster. A tighter suspension won't do much more than the O ring we provide to put under the tube base. The very best way to reduce the vibration is to isolate the preamp from the rack shelf with something very squishy and add mass to the top of the tubes in the manner I did, with the vinyl coated lead flask weights.  When I say mass, I mean MASS. The mass right on the tube envelope has the advantage of reduction of both groundborne and airborne vibration. Mass added to the chassis panel may help a little too.

Obviously keeping the preamp away from speakers, out of corners or areas of the room with antinodes is a useful thing as well.

Perhaps the most effective method to reduce groundborne vibration is to have a listening room with a concrete floor. That will limit the vibration transfer to higher frequencies that are usually easier to address.

Another possible solution would be an isolation platform on an inner tube. Haven't tried that, but with enough mass in the platform on top of the tube it should be fairly resistant to groundborne vibration as well.
Title: Re: The New BeePre Pure Speculation Thread
Post by: makarushka on October 23, 2020, 10:36:02 AM
While "Johnny Jump Up chair" is only a vaguely familiar reference to me, I do get the point :) I had me a feeling. I did what was possible with my BeePre -- dual lead rings on each tube, rubber band under the base (made the least difference), top plate dampened with dynamat and then isolated from the chassis with sorbothane, sorbothane under the chassis, etc. It all helped but fell short still.

Concrete floor indeed would be a solution but is a no-go in my housing situation. A high-end Minus K or Vibraplane isolation platforms would also do the trick, I suspect. Unfortunately, the impossibility of the former and the cost of the latter make a different preamp a more feasible solution :)

I will give a shot to the new one regardless based on the killer sound of the 1st generation. 13dB of microphony reduction as per Paul's post's scenario -- which is likely in my system's gain structure -- is a lot and most likely will make it a non-issue.

Thanks for replying!
Title: Re: The New BeePre Pure Speculation Thread
Post by: Doc B. on October 23, 2020, 11:03:56 AM
Re the CF I had the same concern that the sound might suffer. That actually led to this most recent listening session. I had not heard the earlier prototypes in some time and so PB brought over a basic BeePre 2 prototype along with parts for every possible upgrade version of the new design. This new preamp has a better focused image, cleaner highs that make vocals sound more natural, and quite a bit more punchy bass than the limited edition BeePre 1 I have in my system presently. All in all it gives a more relaxed and natural presentation. I would not have expected this based upon my previous experience with CFs, it was quite a surprise. That's why I refuse to sign off on a design unless I can give it some comparison with a known quantity. You can only think you know what might sound better unless you actually listen and compare. Sometimes you get a surprise.
Title: Re: The New BeePre Pure Speculation Thread
Post by: makarushka on October 23, 2020, 11:20:35 AM
That sounds killer! I am very ready to be surprised -- bring it on :)

And in response to the earlier post regarding messing up tubes by running wrong filament voltage via a switch -- I am that rare individual who's had all manner of gear with switchable filament and B+ voltages, and managed to not mess up once. Yet. It's probably in my future :) So to be able to run a 2A3 as well may seem like a cool option. With that said, personally I would not expect (or desire necessarily) a massively different sound from a [typical modern] 2A3 in a line-drive design that is ultra-optimized for 300B. Unless it was 2A3-40, which is a bit of a waste at regular 2A3 op. points anyway [it can be argued]. Even then, should curiosity become unbearable, I could always try it by stuffing a different set of regulator boards in there that I already have, Coleman or Pete Millett's, depending on what's desired. Probably a switch of a cathode resistor, too -- although maybe not even?

As long as there is enough room inside. For all those fat polyprops and vitreous non-inductive wirewounds and other some such jibberish :)
Title: Re: The New BeePre Pure Speculation Thread
Post by: Paul Birkeland on October 23, 2020, 12:54:14 PM
2A3s will not work in the design and there isn't a good way to make that work without providing a different power transformer and a different circuit.
Title: Re: The New BeePre Pure Speculation Thread
Post by: Alby0521 on November 04, 2020, 03:43:08 PM
Hello

Will the upgrades come available at release date or will you release them later on?

 I already made some space on my rack which is allocated to the beepre ii :) and yes at the moment I became beepreless...
Can’t wait for this winter project.

Best

AB
Title: Re: The New BeePre Pure Speculation Thread
Post by: Paul Birkeland on November 04, 2020, 03:44:59 PM
The upgrades will come a bit after the kit is released. 
Title: Re: The New BeePre Pure Speculation Thread
Post by: Sp33ls on November 16, 2020, 12:06:55 PM
I went to go place an order on the BeePre and was wondering why it was "Out of Stock". Queen pointed me here, and now I'm even more excited. :)

Building this over Xmas would be amazing...  ;) :P

Title: Re: The New BeePre Pure Speculation Thread
Post by: Alby0521 on November 30, 2020, 06:23:27 PM
That’s so true. It would be wonderful to build it over Xmas.

Is that a possibility?

Best

AB
Title: Re: The New BeePre Pure Speculation Thread
Post by: Paul Birkeland on December 01, 2020, 05:43:29 AM
We will be finishing the photo shoot on the manual today.   I suspect ordering will be available before Christmas, but I don't think any kits will ship till after Christmas.
Title: Re: The New BeePre Pure Speculation Thread
Post by: Paul Birkeland on December 01, 2020, 10:51:33 AM
We finished the build/shoot today.
Title: Re: The New BeePre Pure Speculation Thread
Post by: ScottAstroNut on December 01, 2020, 12:21:48 PM
Wow! The stock circuit looks WAY simpler than that of the BeePre I built this past summer. Much more like the Moreplay I built not long ago.

Will the price of the basic kit be less than that of the original BeePre, perhaps?

Scott
Title: Re: The New BeePre Pure Speculation Thread
Post by: Paul Birkeland on December 01, 2020, 12:53:33 PM
The numbers I have pulled together suggest that the new kit will be a little bit less than the old one.  While overall it is far, far simpler and easier to build, the new power transformer is an expensive item and the voltage regulators we are using for the 300B filament are also shockingly expensive. 
Title: Re: The New BeePre Pure Speculation Thread
Post by: Alby0521 on December 12, 2020, 06:51:26 AM
Hello

Do you already have an idea of what tube type will be used in the upgrade described below:

“ The second upgrade module will populate the rear two 9 pin sockets with a dissimilar dual triode that provide individual shunt regulators for both channels as well as adding a cathode follower buffered output that decreases the output impedance of the kit substantially.  This upgrade will also provide balanced outputs similar to the BeePre 1.”

Thanks

AB
Title: Re: The New BeePre Pure Speculation Thread
Post by: Paul Birkeland on December 12, 2020, 06:54:53 AM
Yes, I know exactly which tube it is.  We are working on procuring a large batch to keep the price of the kit stable for a decade or so, so we won't be discussing that until the kit comes out.  As it is now, this particular tube is either around $2-3 from most legit tube dealers or about 10x that much from unscrupulous eBay tube vendors.
Title: Re: The New BeePre Pure Speculation Thread
Post by: Mossback on December 18, 2020, 03:19:03 PM
"Somebody" left their door unlocked and I got a peek at this alleged item. It's a lovely piece of gear looking forward to how it sounds! Well done Bottlehead.
Title: Re: The New BeePre Pure Speculation Thread
Post by: Paul Birkeland on December 18, 2020, 04:26:06 PM
"Somebody" left their door unlocked and I got a peek at this alleged item. It's a lovely piece of gear looking forward to how it sounds! Well done Bottlehead.
I'm glad the safety inspector was over yesterday and not today!
Title: Re: The New BeePre Pure Speculation Thread
Post by: Doc B. on December 18, 2020, 05:27:54 PM
And if you guys follow us on Instagram or Facebook, or are subscribed to the Bottlehead newsletter you will have seen a picture of the finished prototype.

https://www.instagram.com/bottleheadaudio/ (https://www.instagram.com/bottleheadaudio/)

https://www.facebook.com/bottlehead (https://www.facebook.com/bottlehead)

Title: Re: The New BeePre Pure Speculation Thread
Post by: debk on December 20, 2020, 09:54:56 AM
Will it have a similar gain to the current BeePre?  I am able to drive my F4 amp very nicely with the BeePre

Debra
Title: Re: The New BeePre Pure Speculation Thread
Post by: Doc B. on December 21, 2020, 09:19:56 AM
My notes say gain is about 6dB, as opposed to 8.3dB for the original BeePre. So it would require about a click and a half higher setting on the fine control of the BeeQuiet2 stepped attenuator upgrade that will be offered not too long after release of the basic BeePre2. Hopefully PB will verify this - don't always trust my notes.
Title: Re: The New BeePre Pure Speculation Thread
Post by: Paul Birkeland on December 21, 2020, 09:37:29 AM
The gain is a little lower in the stock BeePre 2 compared to the original, but they will even out a bit more with all of the upgrades installed.
Title: Re: The New BeePre Pure Speculation Thread
Post by: Alby0521 on December 22, 2020, 01:06:34 PM
Just ordered one :).
Title: Re: The New BeePre Pure Speculation Thread - Extra Inputs?
Post by: caffeinator on December 24, 2020, 12:29:33 PM
Is there room to add another pair of inputs between the array of inputs and the pair of outputs? I know there appears to be room in the stock configuration; I'm wondering if doing so would interfere with any of the currently planned mods?
Title: Re: The New BeePre Pure Speculation Thread
Post by: Paul Birkeland on December 24, 2020, 12:50:45 PM
Yes, it would interfere with the upgrades a little bit, though you could forego the balanced output part of the upgrade.  You'd also need to figure out a different selector switch.
Title: Re: The New BeePre Pure Speculation Thread
Post by: Chris65 on December 25, 2020, 11:25:46 AM
Yes, I know exactly which tube it is.  We are working on procuring a large batch to keep the price of the kit stable for a decade or so, so we won't be discussing that until the kit comes out.  As it is now, this particular tube is either around $2-3 from most legit tube dealers or about 10x that much from unscrupulous eBay tube vendors.

6C*7?